BIOL 112 1st Edition Lecture 16 Outline of Last Lecture I Background of Form Function II The Digestive System III The Human Digestive System A Pharynx B Esophagus C Stomach D Small Intestine IV Absorption Outline of Current Lecture V Significance of Liver VI Absorption of Water and Salts VII Circulatory Systems VIII Components of Circulation System Current Lecture I Significance of Liver 1st major organ for blood and lymph coming from intestines Hepatic Portal Shunt Blood from the intestines goes through the liver before it goes to the rest of the body liver acts as a filter and a buffer Liver controls nutrient concentrations in blood also detoxifies blood from intestines takes out things that are not healthy and destroys them to regulate blood stream These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute II Absorption of Water and Salts Occurs in Large Intestine Colon End of ileum connects to colon through another sphincter ileocaecal sphincter Caecum In humans this includes the appendix Blind pouch in some animals this is a fermentation site for symbiotic bacteria and protists digesting cellulose Colon Chyme coated with thick mucus Salts removed by active transport through intestinal wall sent to blood Water is removed osmotically when salts are transported out About 90 of water is removed Removal of water coupled with peristaltic movements that pack chyme into a compact mass feces About 30 of feces is dead bacteria Feces propelled to rectum Anus is final sphincter III Circulatory Systems Major function transport of materials throughout body Other services Gas Exchange Transports gasses exchanged for respiration Nutrients Materials picked up by digestive system are distributed throughout body Wastes Products to be removed by excretory system Hormones Communication and control throughout body Body Defenses Inflammatory Immune Systems Types of Circulatory Systems Open Circulation arthropods molluscs Blood is not completely enclosed in vessels throughout circuit to from heart Blood empties into sacs called sinuses which surround many major organs Closed Circulation annelids chordates us Blood is contained entirely in vessels in circuit to from heart Regarded as more efficient because higher blood pressure is maintained in circuit IV Components of Circulation System The Heart as Pump Human heart right left atrium right left ventricle Between each atrium and ventricle valves permits one way flow of blood from each atrium into each ventricle only Atrioventricular Valves Left Mitral Valve Right Tricuspid Valve Between each ventricle and blood vessel Semilunar Valves Heartbeat thub lub Thub AV valves snap shut after atria contract Lub Semilunar valves snap shut after ventricles contract
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